Through the years I have often checked various sources trying to understand what are "biologic therapies" but didn't get any general answer or generalized definition of the term.
Every medical treatment (possibly excluding psychotherapy) is "biological".
It may be a classic case were people try to describe something in too few words, similar to what goes with "Chemical Weapons". Every weapon (possibly excluding psychological warfare) is "chemical", but the term "Chemical Weapons" actually refers primarily to:
Bombs containing strong acids or poison
If I understand correctly, and I don't have a single source for this "biologic therapies" are in general:
Synthetic protein-agonists or synthetic protein-antagonists
A specific example would be TNF-α inhibitors in the treatment of psoriasis(1) but that's only a psoriasis-specific definition, so what are "biologic therapies" in general?